“OCT-A vessel density changes in the macular zone in glaucomatous eyes”. “Diagnostic ability of peripapillary vessel density measurements of optical coherance tomography angiography in primary open-angle and angle-closure glaucoma”. “Optical coherence tomography angiography: Technical principles and clinical applications in ophthalmology”. 6 This is a vision threatening condition and would have been missed if only conventional imaging of the retina was done. OCT-A of this eye has shown abnormal enlargement of the deep capillary network which is indicative of a rare form of macular telangectasia. The retinal blood vessels also appear to be normal on conventional retinal photos. This is a benign and common pathology seen in many eyes that does not require any management and is generally not vision threatening. 8 OCT-A in diagnosing rare macular conditionsĪt first glance, when assessing conventional retinal photos and OCT scans, this eye appears to have vitreomacular traction. Evidence has recently shown that linear vascular dilations and flow-void areas within the retina as seen on OCT-A, precede the appearance of micro-aneurysms and allow earlier diagnosis and detection of diabetic retinopathy. To date, the first sign that an eye is developing diabetic retinopathy is the presence of micro-aneurysms (“out-pouching” of blood vessels). Eyes that are affected by diabetic retinopathy have a significantly reduced choroidal and retinal vascular density as well as an abnormally large foveal avascular zone. OCT-A is the first scan to be able to assess the microvasculature in such high detail. OCT-A in Diabetesĭiabetic retinopathy is the most common ocular complication of diabetes, this is a disease of the microvasculature. The above image shows a OCT-A scan of the superficial capillary network in a glaucoma patient, showing loss of perfusion that corresponds with overlying loss of nerve tissue. 5īy analyzing the blood vessels with the high definition OCT-A scans in combination with conventional OCT, we can detect glaucoma and monitor the risk of glaucoma development much earlier and with greater accuracy. structural glaucomatous changes have occurred without causing a measurable visual defect). 4 This difference is noted prior to any vision loss occurs and may be used to differentiate between healthy eyes and those with pre-perimetric glaucoma (i.e. 2,3 The flow of blood and the amount of blood itself in surface-level vascular perfusion and blood flow density within superficial retinal vessels has been found to be significantly decreased in glaucomatous eyes, when compared to healthy eyes. Recent evidence has shown there is a strong link between the eyes blood vessel network and glaucoma. Due to the insidious nature of glaucoma, it can be difficult to detect and diagnose in the very early stages with conventional imaging. In the early stages, people with glaucoma don’t notice any vision loss. Glaucoma is a progressive eye disease that causes gradual optic nerve damage over time. Because the only thing that is changing and moving as the scan is being taken are the blood cells, the OCT-A scan can track and assess the flow of blood. When multiple OCT scans are taken of the same location, changes in the reflection pattern over time can be used to produce another specialised scan – the OCT-A scan. The optometrists at Innovative Eye Care use the top of the range Heidelberg Spectralis OCT-A to obtain high-quality, precision images at high speeds.Ĭonventional OCT scans assess the eye’s structural integrity by analyzing light that is reflected from the back of the eye (the retina). OCT-A gives insight into small changes to the blood vessel network before they develop, making it particularly useful for early diagnosis and monitoring of retinal eye diseases, including glaucoma, macular degeneration, choroidal neovascularization, diabetes, vein occlusions and optic neuropathies. Optical coherence tomography angiography (OCT-A) is a non-invasive scan that creates a three-dimensional image of the network of blood vessels in your eye by tracking individual blood cells.
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